BEIJING, Feb 6 (Reuter) - Some 800 aftershocks have rattled southwest China's Lijiang since a killer weekend earthquake, hampering mountain relief work as the tally of shattered homes soared to 330,000, officials said on Tuesday.

Braving an unusual freeze, many of the hundreds of thousands of people left homeless by Saturday's 7.0-magnitude earthquake huddled in terror outdoors rather than enter damaged houses as the earth continued to shake, they said.

The death toll has climbed to 246 with 15,000 injured, 3,837 of them seriously, said rescue coordinators reached by telephone on Tuesday in the Yunnan provincial capital, Kunming.

More than 3,000 troops and armed police were sent from neighbouring Sichuan province to help 2,000 soldiers already scouring the rubble of mud-brick homes in mountain villages. The death toll could rise to over 300, officials said.

The tally of collapsed homes had surpassed 330,000, a sharp rise over the 186,000 counted on Monday, as new reports trickled in from the most isolated mountain areas, they said.

Entire villages were obliterated. Warm clothing, shelter and medicine were in desperately short supply, officials said.

Relief supplies from China and overseas had begun pouring in to the mountainous region of Yunnan province, accessible from Kunming only by small aircraft or a difficult, daylong drive over rutted, twisting roads.

Beijing pledged 20 million yuan ($2.4 million) in new state emergency aid as well as 5,000 tonnes of fuel, 100,000 padded garments and hundreds of tents, the Xinhua news agency said.

Some 80 million yuan ($9.6 million) in aid was delivered on Monday, including cash and kind donations from Taiwan, Hong Kong and Japan as well as Chinese agencies, firms and individuals.

Top priority was airlifting clothing, quilts, medicine and tents to Lijiang, a region 2,000 km (1,300 miles) southwest of Beijing. The region is known for its scenic beauty, with ethnic Naxi villages nestled below snow-capped Jade Dragon Snow Mountain.

More assistance was needed despite a good initial response to Sunday's Red Cross of China appeal, officials said.

"We really need whatever emergency help the world can offer," one relief official pleaded by telephone from Lijiang late on Monday.

None of the nearly 800 aftershocks recorded as of Tuesday morning registered more than a 6.0-magnitude shock that jolted residents in Monday's early-morning darkess, officials said.

The main tremor on Saturday was the worst in Lijiang since the 15th century and China's deadliest in eight years.

An American tourist who suffered serious injuries at Tiger Leaping Gorge on the Yangtze river was "not in danger of dying" and taken with 21 fellow foreign travellers to a safe area. Four others had slight injuries, an official in Kunming said.

"The American man was physically pinned in a mountainous area and had to be extricated by soldiers," he said.

The other foreigners' identities were not available, he said. Yunnan Governor He Zhiqiang issued 10 directives to rescue workers. Priorities were burial of bodies and dead livestock, caring for the injured, preventing disease and obtaining "pots to cook and rice in the pots" for the homeless.

China's most serious earthquake in recent years was in 1988, also in Yunnan province, when a tremor measuring 7.6 killed 939 people near the border with Burma.

The most recent tremor in Yunnan, which lies on a major fault, was a 6.5 earthquake that rocked an area near Kunming in October 1995, killing 44.